face down vs prostrate

face down

verb
  • To confront; to abash by stern looks. 

prostrate

verb
  • To overcome or overpower. 

  • To throw oneself down in submission. 

  • To lie flat or face-down. 

  • To cause to lie down, to flatten. 

adj
  • Lying flat, face-down. 

  • Physically incapacitated from environmental exposure or debilitating disease. 

  • Trailing on the ground; procumbent. 

  • Emotionally devastated. 

How often have the words face down and prostrate occurred in a corpus of books? (source: Google Ngram Viewer )